DE2711005C3 - Process for the direct and electrolytic production of metal-free phthalocyanines - Google Patents

Description

The invention relates to a process for the preparation of metal-free phthalocyanines from aromatic ones o-dicarboxylic acid nitriles.

For the production of metal-free phthalocyanines direct and indirect manufacturing processes are known The technical manufacture of metal-free Phthalocyanine is made by indirect processes, at which initially an alkali metal or alkaline earth metal phthalocyanine is produced, which is then demetallized (US-PS 21 16 602 and 3060189). The indirect processes usually give higher yields Phthalocyanine, but this requires more work and equipment.

Process for the direct production of metal-free phthalocyanines - hereinafter referred to as PC - are known for example from US-PS 21 16 602 and GB-PS 4 10 814. Thereafter, o-phthalonitrile is in Presence of catalytically active basic compounds

j5 gene cyclized to PC

Furthermore, by heating o-phthalonitrile in polyols (DE-PS 6 96 334), o-cyanobenzamide (US-PS 20 00 051 and 20 00 052) and of mixtures of phthalic anhydride, urea and ammonium salt zen in the presence of antimony catalysts free phthalocyanine (US-PS 28 20 796 - albeit in uneconomical yields and / or in impure Shape - to be preserved. The object of the present invention was to provide a j to find a process for the production of metal-free phthalocyanine, according to which aromatic o-dicarboxylic acid dinitrile in high yield at the same time can be converted into the corresponding PC connections with little expenditure on equipment.

• 50 It has been found that metal-free phthalocyanine can be obtained directly from aromatic o-dinitriles in organic liquids at high temperatures in high yield if one uses primary, secondary or tertiary Ci- to Ci ₂ -alkanols, C ₂ - to Ce- Alkanediols,

v-, C ₃ - to Ce-alkanediols, poly-C ₂ - to Ce-alkanediols, poly-C ₃ - to Ce-alkanediols, saturated cyclic ethers with 4 and 5 C-atoms, N-Ci- to Q-alkyl - or N, N-bis (Cr to Q-alkylJ-carboxamides of aliphatic Ci- to Cj-carboxylic acids, cyclic N * C | -

M) to C ^ alkylcarboxamides with 4 to 6 carbon atoms or mixtures thereof, benzene hydrocarbons or chlorinated benzene hydrocarbons containing small amounts of dissolved electrolytically conductive Tetraalkylammonium salts, tris (hydroxyalkyl) -alkyl-

_h -, ammonium salts, tetra (hydroxyalkyl) ammonium salts, salts of primary, secondary or tertiary alkylamines or hydroxyalkylamines with 1 to 20 carbon atoms in the alkyl and / or 2 or 3 carbon atoms in the

Hydroxyalkyl, hydrochloric acid, sulfuric acid, Q- to Ce-alkanesulfonic acid, benzenesulfonic acid, C ₁ - to Cg-alkylbenzenesulfonic acid, Q- to C ₅ -alkylsulfuric acid, mono- and / or Dj-Ci- to Q _g - Alkyl phosphoric acid; Ammonium salts, alkali metal or alkaline earth metal salts of benzenesulfonic acid, Q- to Qs-alkylbenzenesulfonic acids, naphthalenesulfonic acids, C | - to Cg-alkylnaphthalenesulfonic acids, Q- to Ce-alkanesulfonic acids, Cr to Ce-chloroalkanesulfonic acids, of hydroxy-Cr to Ce alkanesulfonic acids, the Q- to Q-alkylsulfuric acids, the C ₂ - to Q-chloroalkylsulfuric acids, the mono- or di-Q- to Ci8-alkylphosphoric acids, the mono- and di-Q- to Qe-alkyl esters of boric acid, the cyclic esters boric acid with 1,2- and 1,3-diols and / or CU to Ce dicarboxylic acids bearing sulfonic acid groups; Q to Qr alkanolates, C ₂ to Ce glycolates, hydroxides, amides, sulfides, rhodanides and / or cyanides of the alkali metals and alkaline earth metals, magnesium or lithium chloride contain dissolved or suspended dinitriles in the presence of hydrogen or a compound which splits off hydrogen under the reaction conditions and in the presence of alkali metal alcoholates ^ alkali metal sulfides, alkali metal hydroxides, alkali metal cyanides, alkali metal salts of mono- and di-Q- to Qe-alkylphosphoric acids, alkali metal amides, alkali metal salts of mono- and di-Q- to Cig-alkyl esters of cyclic boric acid esters , 2-, 2β- and 1,3-diols and / or alkali metal salts of Ct- bis (! ^ - dicarboxylic acids bearing sulfonic acid groups as alkaline activators using electrodes which are inert under the reaction conditions are electrolyzed in such a way that the hydrogen overvoltage at the cathode is 50OmV (measured against the reversible hydrogen electrode in a m medium of the same composition as the reaction mixture) does not exceed.

The PC produced during electrolysis usually falls in the form of long needles with a purity of 90% and above.

By choosing optimal conditions, the purity of the process product can be increased to 98% to 99% can be increased.

In DE-PS 12 34 342 a process for the production of PC from o-phthalonitrile and hydrogen under high pressure (50 to 400 atmospheres) at temperatures between 100 and 500 ^° C. is described. According to the information in the examples, the PC yields are around 80% of theory. Since the process product contains unreacted dinitrile and decomposition products of the dinitrile, the process product is extracted. It is known to the person skilled in the art that impurities enclosed by PC cannot or cannot be completely removed in this way. Since the purification possible with CuPc by dissolving from concentrated sulfuric acid cannot be used in the PC on an industrial scale (the PC is decomposed by the sulfuric acid with oxidation), the process product is not suitable for pigment purposes. Furthermore, the outlay on equipment for the process described in DE-AS 12 34 342 is very large, so that economical production is not possible.

In US-PS 34 92 308 a process for the production of PC suitable for photoconductive purposes by heating optionally substituted o-phthalonitrile or nitrogen-containing phthalic acid derivatives in N-alkylalkanolamines in the presence

of amines, in particular of ammonia. It is known that only the o-dinitriles give PC under the specified conditions. So among the im Example II specified conditions PC obtained in about 40% of the theoretically possible yield with a purity of about 90% by weight. According to the information of Example VIII, as expected, no PC is obtained.

In US-PS 35 09 146 the production of PC suitable for photoconductive purposes from 1,3-diimino-isoindoline by heating in N-alkylalkanolamines to 100 to 280 ° C. is described. According to the information in the examples, the yields should be 80 to 85% of the theoretically possible yield ^{after just 10 to 30 minutes at 131 to 200 ° C.} Examples 1 and 2 of US-PS 35 09 146 were reworked The yields and the purity of the isolated product are summarized in the table:

U.S. Patent 3,509,143 Example I.

Pc
yield
²⁵ [% of theory Purity
[% By weight] reaction time
at 131-135 C U
9.0
JO 45.5 99.5
99.5
84.1
Example 2 10 mins
4 hours
8 hours J5 PC
yield
[% of theory] Purity
[% By weight] reaction time
at 131-135 C

2.8 9.6

99.7 99.7 99.5

25 minutes 90 minutes 3.5 hours

That is, the achievable by the process of US-PS 35 09 146 yields are for an industrial Manufacturing process of PC for pigment purposes is far from sufficient. In addition there is the Disadvantage that with prolonged heating the proportion of by-products in the process product increases, making the product unusable for pigment purposes will.

Another method of making PC is from Ann. 658, pages 21 to 38 are formed (1962) Thereafter, known to lOstündiges by heating o-phthalodinitrile with Natriumtetraamyloxyboranat Na B (OCsHt 1) 4 to 250 to 260 ⁰ C in 71- to 81% yield PC. With sodium amylate in amyl alcohol, 60 to 68% of theory of PC are obtained, according to the information, by heating at 150 ° C. for 10 to 20 hours. The former process is not suitable for industrial implementation, since, because of the high reaction ^{temperature of 250 to 260 °} C., side reactions of the dinitrile take place, so that the process product is not suitable for pigment purposes. For this reason, the process product was probably redissolved from sulfuric acid, but this did not achieve any cleaning effect. Thus, according to the process with amyl alcohol / sodium amylate at 150 ° C., 72% of the PC was obtained

Theoretically possible yield isolated, but the process product failed - despite gentle dissolution from ice-cold sulfuric acid and precipitating on ice - only has a purity of 72% by weight. That means that Product is unsuitable for pigmentation purposes.

In contrast, o-Phthalonitri succeeds in the process of the present invention! in high Yield and to be converted into PC on an industrial scale, which has a purity of 90 to 99% by weight Since the mother liquor after the separation of the PC formed and after the replenishment of the consumed Dinitrile and the other components discharged with the PC again for the electrolysis can be used, the dinitrile succeeds in this way practically quantitatively in PC of high purity to convict.

As the aromatic o-dinitriles suitable for the novel process, the benzene and naphthalene into consideration, besides the aromatic radicals further substituents such as Ci can -C ₄ -alkyl, phenyl, phenoxy, halogen or nitro wear. Mixtures of different o-dinitriles can also be used. As aromatic o-dinitriles, for. B. to be mentioned in detail:

o-phthalonitrile.'t-chlorophthalonitrile,
Tri- and tetrachlorophthalodinitrile,
Methylphthalodinitrile,
4-phenylphthalodinitrile,
4- phenoxyphthalonitrile,
2,3-naphthodinitrile,
4-nitrophthalodinitrile and
4-aminophthalonitrile.

The process is generally carried out in such a way that the aromatic o-dinitrile is converted into the organic Since the reaction takes place essentially on the dissolved dinitrile, the dinitrile should be in the organic liquid be at least partially soluble at the reaction temperature. This condition can can easily be met by selecting suitable organic liquids.

The organic liquid contains small amounts of dissolved electrolytically conductive compounds, thus the mixture has sufficient conductivity for electrolysis Electrodes are electrolyzed with direct current, at the same time the mixture is constantly z. B. by stirring or well mixed by introducing gas

The voltage between anode and cathode is expediently regulated so that the current density at the cathode is 500 to 10,000 A / m ² . You can also work with lower current densities, but then the space-time yield drops.

The applied voltage is also due to the overvoltage of the hydrogen occurring at the cathode, which depends on the cathode material. So that no reduction of the dinitrile and / or of the PC occurs, the hydrogen overvoltage should be 500 mV (measured against the reversible hydrogen electrode in the same organic liquid). The electrolysis is preferably carried out so that the hydrogen overvoltage at the cathode is below 500 mV.

It should also be noted that the anode potential! not greater than the oxidation potential of the organic Liquid wiid, otherwise o-dinitrile and resulting PC can be oxidized.

The electrolysis is expediently up to a conversion of 70 to 95%, preferably carried out up to a conversion of 80 to 90% of the phthalonitrile This results in a significantly higher current yield and, at the same time, a significantly higher space-time yield achieved than in the implementation of more than 95%, up to the quantitative implementation of the dinitrile, since with increasing dinitrile depletion of the liquid, the current yield drops significantly

in Since the liquid separated from the PC after the addition of the missing components such as phthalonitrile, if necessary, electrolytically conductive compounds and activators, is reused, goes with the non-quantitative conversion no starting product is lost. However, with this procedure of the only 80-90% conversion, a high current yield and at the same time a high space-time yield achieved, which is why this variant of the method is preferred

Since the reaction proceeds more readily in the -wesentlich warms the electrolysis is carried out vorteüliafterweise at temperatures above 40 ⁰ C. The upper temperature limit is determined by the boiling point of the organic liquid. However, you can also work under Druct and so at temperatures above the boiling point of the liquid. Preferably, one works at temperatures between 60 ⁰ C and the boiling point of the organic liquid, in particular at temperatures between 80 and 120 ° C, gegebenen-

jo if under pressure.

_{Primary, secondary or tertiary C 1} to C 2 alkanols, which can be linear or branched in the alkane radical, are particularly suitable as organic liquids. In addition, C 2 - to Ce alkanediols, C ₃ - bis

j5 Ce-alkanediols, poly-C ₂ - to Q-alkanediols, poly-C ₃ - bis (valkanetriols, saturated cyclic ethers with 4 or 5 carbon atoms and N- (C) - to Q-alkyl) - or N ₁ N- (Ci- to Gi-dialkyl) -imides of aliphatic Ci- to C ₃ -carboxylic acids, cyclic N-Ci- to C ^ alkylcarboxamides with 4 to 6 carbon atoms or mixtures thereof as organic liquids.

Furthermore, aromatic benzene hydrocarbons such as benzene, toluene, Xylene and chlorinated benzene hydrocarbons such as

4> chlorobenzene, o-dichlorobenzene, trichlorobenzene, chlorotoluene and the chloroxylenes into consideration.

As organic liquids are, for. B. to be mentioned in detail:

λ) Cr to Ci2-alkanols:
Methanol, ethano ', propanol, isopropanol,
Bijtanol, isobutanol, sec-butanol,
tert-butanol, amyl alcohol, isoamyl alcohol,
secAmylalkciiol, n-Hexanol, Isohexano ',
n-heptanol, isoheptanol, n-octanol,
Isooctanol, 2-ethyl-hexanol, n-nonanol,
Isononano !, n-decanol, isodecanol,
n-dodecanoi and isododecanol;

ß) C ₂ - to Ce-alkanediols and C ₃ - to Ce-AIUantriole and their polyethers:

Ethylene glycol. Diethylene glycol,

Triethylene glycol,

Polyethylene glycol with 4 to 6 glycol units,

Propylene glycol-1,2, propylene glycol-1,3,

DiDroDvlenelvkol.

Polypropylene glycol with

3 to 6 propylene glycol units,
Glycerine, butane-1,2,4-triol, butanediol-1,4,
1,3-butanediol, 1,5-pentanediol and
1,6-hexanediol;

γ) cyclic ethers:
Tetrahydrofuran, hydropyran and dioxane;

δ) aliphatic Cr to Ca carboxamides and cyclic carbonamides:

Formamide, N-methylformamide,
Ν, Ν-dimethylformamide, N-ethylformamide,
Ν, Ν-diethylformamide, N, N-dipropylformamide,
Dimethylacetamide. N, N-diethylacetamide,
N, N-dipropylacetamide,
N, N-dimethylpropionamide,

κι κι n: u »i ... i:: ~ j

! ^, i ^ -L / iatiivipiispii / iiaiiiiu,

N, N-dipropylpropionamide, pyrrolidone,
N-methylpyrrolidone, N-methylcaprolactam,
N-ethyl-, N-butyl- and N-propylcaprolactam.

Mixtures of different liquids can also be used as the reaction medium.

Of the organic liquids mentioned, the Cr to C ₆ alkanols are preferred. Of these, in turn, the Cr to Cv are alkanols, such as propanol. Isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol. n-Hexanol, sec.hexanol and isohexanol are particularly preferred, since high yields of PC are obtained in these and the reaction mixture can be worked up by filtering and simply drying the organic liquid adhering to the PC.

The lower limit of the amount of organic liquid is determined by the reaction mixture must be well mixable before, during and after the reaction.

As a rule, 4 to 40 times the amount of o-dinitrile used is used, preferably 10 to 20 times the weight.

Since the oPhthalonitrile undtr the conditions of the salts, salts of primary, secondary or tertiary alkylamines or hydroxyalkylamines, the alkyl groups having 1 to 20 carbon atoms and the hydroxyalkyl groups having 2 or 3 carbon atoms

-, and if there is more than one alkyl and / or hydroxyalkyl the groups can be the same or different and these ammonium salts as anions those of hydrochloric acid, sulfuric acid, Cr to Ce-alkyl sulfonic acids, benzenesulfonic acid, the

in Ci- bis (^ -alkylbenzenesulfonic acids, the Cr bis C5-alkylsulfuric acids (sulfuric acid half-esters from Cr to Ci-alkanols), the mono- and / or Contain di-Cr to Cie-alkyl phosphoric acids;

b) NH ₄ * alkali metal or alkaline earth metal salts of ii benzenesulphonic acid, Cr to Cie-alkylbenzenesulphonic acids, naphthalene stilfonic acid, Cr to Ca-alkylnaphthalenesulphonic acid, Cr to Ce-ΑΙ-kanesulphonic acids, C2- to Ce-chloroalkanesulphonic acids. the hydroxyl to Cs-alkanesulfonic acids.

in the Cr to CVAIkylschwef'elsäuren, the C2 bis Ce-chloroalkylsulfuric acid, the mono- and Di-Cr to Cts-alkyl esters of boric acid or Phosphoric acid, the cyclic ester of boric acid with 1,2- and 1,3-diols with 2 to 8 carbon atoms and

r, of dicarboxylic acids containing sulfonic acid groups and having a total of 4 to 6 carbon atoms;

c) Cr to Cir alkanolates, C ₂ - to Ct glycolates, hydroxides, amides, sulfides, rhodanides, cyanides of the alkali metals and the alkaline earth metals and

in d) chlorides of the alkaline earth metals and alkali metals (as far as these are soluble in the organic liquids used), such as magnesium chloride and lithium chloride.

3-, A prerequisite for the suitability of the connections is that they are in the above-mentioned extent in the organic liquids used are soluble.

As cations of the mono-, di-, tri or Tetraa'kylamiTioniumsalze mentioned under a) z. B. in detail

4 "to be named:

it is expedient to use organic liquids which contain as little water as possible. The water content should advantageously be less than 0.1% by weight, based on the organic liquid, lie. At higher water contents, the saponification increases the yield of the process product significantly reduced.

So that the organic liquid has sufficient conductivity for electrolysis, contains the liquid organic phase contains small amounts of electrolytically conductive compounds. The quantities are generally between 0.001 and 5, preferably 0.01 and 3, in particular between 0.1 and 1 percent by weight, based on the organic liquid

Ionic organic and inorganic compounds are used as electrolytically conductive compounds Consider which are sufficiently soluble in the organic liquids for the stated purpose and their Cations and anions under the conditions of electrolysis neither with the o-dinitrile, which is formed PC still react with the organic liquid.

The following electrolytically conductive connections can be considered:

a) Tetraalkylammonium salts, tris (hydroxyalkyl) -alkylammonium salts, tetra (hydroxyalkyl) ammonium-tetrapropylammonium, tetrabutylammonium,
Dodecyltrimethylammonium,

₄ -, trimethylethylammonium,
Trimethyl-butylammonium,
Trimethyl-hexy! Ammonium, trimethylammonium,
Triethylammonium, tripropylammonium,
Tributylammonium, dimethylammonium,

- ", diethylammonium, dipropylammonium,
Dibutylammonium, dihexylammonium,
pioctylammonium, methylammonium,
Ethylammonium, Propylammonium,
Butylammonium, hexylammonium,

Octylammonium, decylammonium,

Dodecylammonium, hexadecylammonium,
Octadecyl ammonium, ethanol ammonium,
Diethanoiammonium, triethanolammonium,
Propanolammonium and dipropanolammonium.

As anions for these ammonium ions, for. B.

Hydrogen sulfate, sulfate, chloride,
Benzenesulfonate, o- and p-toluenesulfonate,
Ethylbenzene, propylbenzene, butylbenzene,
Hexylbenzene, octylbenzene and

Nonylbenzenesulfonate,

Methane, ethane, propane, butane, pentane and
Hexanesulfonate, methyl, ethyl, propyl and

27 Π

ίο

Butyl sulfuric acid, monododecyl phosphate, monoheptadecyl phosphate and
Bis (2-ethylhexyl) phosphate

into consideration.

As alkali metal and alkaline earth metal ions for the groups mentioned b) and c) are above all the of sodium, potassium, lithium, calcium and magnesium.

For the sulfonic acids mentioned under b) z. B. in detail in addition to benzenesulfonic acid and naphthalenesulfonic acid as C _r to C | _8- Alkylbenzenesulfonic acids, of which those with Ci- to Cg-alkyl are preferred, those of the

Toluene, ethylbenzene, propylbenzene, butylbenzene, hexylbenzene, octylbenzene, Nonylbenzene, decylbenzene, dodecylbenzene,

0-hydroxybutanesulfonic acid and
0-hydroxyhexanesulfonic acid;
Potassium or sodium salts

the methyl, ethyl, propyl, chloropropyl,
■ -, butyl and hexyl sulfuric acid

(= Salts of the sulfuric acid half esters of
Ethanol, propanol, butanol and hexanol),
Sodium or potassium salts

the sulfosuccinic acid as well
in sodium and potassium hydroxide

used.

In the process according to the invention, the electrolysis also takes place in the presence of alkaline substances Agents as activators for the o-dinitrile. As activators, z. B. Alkali metal amides and alkaline acting electrolytically conductive compounds, such as alkali metal alcoholates, alkali metal sulfides, alkali metal

Octadecylbenzene
into consideration.

As alkylnaphthalenesulfonic acids are, for. B. methylnaphthalene sulfonate,
Butyl naphthalene sulfonate
to call.

As alkanesulphonic acids and chloroalkanesulphonic acids _> -, come z. B.

Methane, ethane, propane, chloropropane, butane, chlorobutane, pentane and Hexanesulfonic acid

and .Jr the alkylsulfuric and Chloralkylschwe- j ₍₎ feisäuren z. B.

Methylsulfuric acid, ethylsulfuric acid, propyl, chloropropyl, butyl,
Chlorobutyl and hexyl sulfuric acid into consideration. r,

Particularly suitable hydroxy-Cr to Ce-alkanesulfonic acids are those with a hydroxyl group in the ^ position. In detail z. B.
jS-Hydroxyethanesulfonic acid,

/ J-Hydroxyprupansuii'jiicäure,

S-hydroxybutanesulfonic acid and ß- hydroxy hexanesulfonic acid
to call.

Of the mono- and dialkylphosphoric acids there are, for example, 4,

Monododecyl phosphoric acid,
Monoheptadecyl phosphoric acid, bis (2-ethylhexyl) phosphoric acid, mono-2-ethylhexyl phosphoric acid

are considered, these acids are preferably used in form _{V) of} the alkali metal or alkylammonium salts.

As sulfonic acid groups-containing dicarboxylic acids are, for. B. sulfosuccinic acid and sulfoglutaric acid to call.

In the process according to the invention, the electrolytically conductive compounds are preferably tetraethylammonium salts
of ethylsulphuric acid,

o- and p-toluenesulphonic acid, eo

of p-butylbenzenesulfonic acid and p-hexylbenzenesulfonic acid; Sodium and potassium salts

propane and chloropropane sulfonic acid, butane and hexane sulfonic acid; Sodium and potassium salts

of 0-hydroxyethanesulphonic acid, ß-hydroxypropanesulphonic acid,

of mono- and di-Ci- to Cie-alkyl phosphoric acids, alkali metal salts of mono- and di-Ci- to C ₁₈ -alkyl esters of boric acid and alkali metal salts of cyclic boric acid esters with 1,2- and 1,3-diols such as ethylene glycol, 1,2 and propanediol and 1,2, 2,3 and 1,3 butanediol and the alkali metal salts of dicarboxylic acids bearing sulfonic acid groups. Of the basic alkali metal salts, the lithium, potassium and sodium salts are preferred.

Potassium and lithium amides, preferably sodium amide, are suitable as amides. As alkanolates especially those with potassium and lithium come, especially those with sodium from Cr to Q-alkanols into consideration. Of these, sodium methylate, sodium ethylate, sodium propanolate, sodium and potassium tert-butoxide particularly preferred as these are easily accessible.

The amount of activators is generally 0.1 to 1.0% by weight, based on organic Liquid. From 03 to 0.5% by weight of activators are preferably used. Is used for the invention Process A'kanoie as an organic liquid and reaction medium, then forms at Use of amides as activators, the corresponding alcoholates with evolution of ammonia. in the Case of using alkaline electrolytically conductive compounds as activators At the same time, they also give the reaction medium the required electrical conductivity

Compounds that split off hydrogen are, for. B. easily dehydrogenatable lower alkanols such as methanol, Propanol, isopropanol, lower aldehydes such as formaldehyde or acetaldehyde or alkali boronates how

Lithium borohydride, sodium borohydride,
Potassium borohydride, lithium aluminum hydride,
Sodium cyanoborohydrides, aminoboranes,
Sodium aluminum bis (2-methoxyethoxy) -

dihydride,

9-borabicyclo- (33, l) -nonane and
Lithium trimethoxyborohydride

into consideration The alkali boronates can also be used in the presence of hydrogen. However, preference is given to working in the presence of hydrogen, which is finely divided into gas into the reaction mixture.

The electrodes used in the process according to the invention must be subjected to the reaction conditions be inert, d. H. they must not go into solution or with the o-dinitrile and / or with the resulting PC

react, ζ. B. with the formation of complexes. Accordingly, those for the cathode and the anode are increased using materials made different requirements.

The inert materials for the cathode are τ. Β. into consideration: titanium, zircon, tantalum, graphite, stainless steels, brass, copper, silver, gold, zinc, tin, antimony; Titanium, tantalum, aluminum, graphite, copper, silver or stainless steel coated on the surface with nickel borides, titanium borides, zirconium borides or tantalum borides; Plates or rods made from nickel borides, tantalum borides, titanium borides or zirconium borides.

Other borides, nitrides, and silicides can also be used as inert materials for the cathode and / or carbides of metals from IV. to Vl. Subgroup of the periodic system used will.

The cathode used is preferably those materials which are present in the reaction medium used have a medium hydrogen overvoltage in order to avoid hydrogenation of double bonds and still achieve a good electron transfer. For the purposes of the present invention, under average hydrogen overvoltage from 50 to 500 mV (measured against the reversible hydrogen electrode in the same medium).

For this reason, copper, silver, gold, tantalum, titanium and stainless steels are special as cathode materials suitable and therefore preferred.

A conductive material is used for the anode, which is not anodic under the reaction conditions Oxidation goes into solution. Substances that are inert under these conditions are e.g. B. Consider: graphite, Glass graphite; the carbides and borides of nickel, titanium, zirconium and tungsten; the platinum metals; with Platinum metals or gold coated or doped titanium, tungsten oxide, molybdenum oxide and molybdenum carbide as well as activated nickel or activated cobalt.

Carbides, borides, silicides and nitrides of other metals can also be used as anode material IV. To VI. Subgroup of the periodic system, as well as metals of the viii. Subgroup of periodic table or gold doped silicon carbide and boron carbide can be used.

The anode material used is preferably nickel boride, activated nickel, activated cobalt, Graphite, platinum metals, as well as tungsten oxides doped with metals of subgroup VIII or gold, Molybdenum oxides, tungsten carbides, molybdenum carbides, zirconium borides and zirconium carbides and doped with platinum Titanium.

The electrodes as a whole can consist of the materials mentioned. The materials can also be used as Layer be applied to an electrically conductive base.

Of the materials mentioned, the doped oxides, as well as activated nickel and cobalt can only can be used as an anode together with hydrogen.

The electrodes can take the form of plates, rods, perforated plates, pipes, nets, expanded metal nets, granules, Wool and also of finely divided material.

Advantageously, for. B. anode and cathode in the form of plates in filter press, capillary gap and Tubular cells can also be used, in which it is expedient to use the inner surface of the outer tube the anode and a centrally arranged rod or a centric attached pipe dir. Cathode is.

Another advantageous embodiment of the cell

contains anode and cathode in the form of expanded metal meshes or perforated plates, with during the electrodes are flowed through by the reaction mixture during electrolysis.

The arrangement as a floor cell is particularly advantageous, in which anode and cathode alternate, separated by a space. ίο The cathode and anode in this cell are preferably in the form of expanded metal meshes or perforated plates.

Granules and finely divided material are used as electrode material in vortex processes, whereby the electrical connection of the vortexed particles or granules through into the vortex space protruding rods is made. These rods also serve as electrodes.

The following examples are intended to explain the process according to the invention further. The percentages relate focus on the weight.

The specific surface (BET surface) was determined according to St. B r u η η e r, P.H. E m e t and E. T e 11 e r, J. Amer. Chem. Soc. 60, 309 (1938). the Hydrogen overvoltage was in all cases against the reversible hydrogen electrode in a medium measured, which has the same composition as the reaction mixture.

example 1

jo In an electrolysis cell containing a stainless steel cathode containing chromium and nickel and a graphite anode coated on the surface with nickel boride (surface 50 cm ² ), a solution of 100 g of o-phthalonitrile, 900 g of isobutanol, 2.5 g of sodium methylate and 20 g Given tetraethylammonium ethyl sulfate. The electrolysis is carried out while introducing hydrogen at 90 ^° C. with a current density of 2000 A / m ² at the cathode. The hydrogen overvoltage was below 500 mV (measured against

to the reversible what, «. T <-! fabric electrode in the same Medium).

The reaction was over after 12 Ah. 85 g of metal-free phthalocyanine (PC) in the form of needles are isolated from the reaction mixture, purity: 95%, BET specific surface area of 7 to 8 m ² / g.

C ₃ 2Hi ₈ N ₈ (M.514.6)

Ber. C 74.7, H 3.5, N 21.8%,
found C 74.6, H 3.8, N 21.5%.

Example 2

The procedure is as indicated in Example 1, but instead of the graphite anode, a titanium anode which is superficially covered with an alloy of 70% platinum and 30% iridium

86 g of PC, which has a purity of 96% and a specific surface area of 6 to 7 m ² / g, are isolated

Ber. C 74.7, H 3.5, N 21.8%,
found C 74.4, H 3.7, N 21.7%.

Example 3

The procedure is as in Example 2, but instead of isobutanol, the same amount of diethylene glycol is used

col. After working up, 82 g of PC are obtained. Purity 95%; BET specific surface area 7 m ² / g.

C ₃ 2Hi ₈ N ₈ (M.514.6)

Ber. C 74.7, H 3.5, N 21.8%,
found C 74.5, H 3.7, N 21.6%.

Examples 4 to 9

The procedure is as indicated in Example 1, but instead of isobutanol, the same amount of the in organic liquids specified in the following table.

Hot example liquid Pc R, complied with yield
G on the PC 4th glycol monomethyl 90 94 iither 5 n-butanol 90 96 6th n-hexanol 94 98 7th Isooctanol 90 92 8th n-nonanol 86 90 9 1,4-dioxane 65 90

The BET surface area of the PC obtained is 6 m ² / g. so

Example 10

An electrolysis cell with a copper cathode (area: 51 cm ² ) and a graphite anode (area 50 cm ² ) is used. j-,

A solution of 90 g of 4-nitro-o-phthalonitrile, 2.5 g of sodium methylate and 20 g of tetraethylammonium-p-toluenesulfonate in 950 g n-hexanol at 90 ⁰ C and simultaneous introduction of hydrogen at a käihüdischen current density of 800 A / m 'cicktrolysicrt. ., o The hydrogen overvoltage was a maximum of 400 mV (measured against the reversible hydrogen electrode in the same medium).

Filtration gives 89 g of greenish blue fine crystals, 90% of which are tetranitrophthalocyanine exist.

C ₃₂ H, ₄ N ₁₂ O ₈ (M.694.6)

Ber. C 55.3, H 2.0, N 24.2, O 18.4%, found. C 55.2, H 2.8, N 23.8, O 18.8%.

Example 11

The procedure described in Example 10 is followed, except that 100 g of 4-phenyl-o-phthalonitrile and 1000 g of isobutanol are used as organic liquid, temperature: 85 ° C., cathodic current density: 2000 A / m ² .

After working up, 89 g of turquoise-colored fine crystals are obtained, 90% of which are tetraphenylphthalocyanine exist.

Cathodic current density: 1500 A / m ² ,

Temperature: 120 ° C.

Yield 88 g of turquoise fine crystals composed of 94% tetraphenylphthalocyanine.

C ₅₆ H ₃₄ N ₈ (M. 818.9)

Ber. C 82.1, H 4.2, N 13.7%,
found C 81.4, H 4.2, N 13.5%.

_{1 ()} Example 13

The procedure described in Example 10 is followed, except that a solution of 100 g of 4-chlorophthalodinitrile, 2 g, is used Sodium amide and 25 g of the sodium salt of propanesulfonic acid in 900 g of isobutanol.

i) current density: 4000 A / m ² at the cathode,
Temperature: 95 ° C,

Hydrogen overvoltage maximum of 450 mV (as measured against the r? ^V? Rsible hydrogen electrode).
Yield: 95 g of turquoise crystals, 90% of which consist of tetrachlorophthalocyanine.

C ₃₂ H, 2N ₈ Cl ₄ (M. 650.3)

Ber. C 59.1, H 1.9, N 17.2. Cl 21.8%,
found C 57.9, H 2.2, N 16.8, Cl 22.5%.

Example 14

The procedure described in Example 13 is followed, except that 100 g of tetrachloro-o-phthalonitrile are used as the dinitrile.
Temperature: 95 ° C,
Cathodic current density: 4000 A / m ² ,
Yield: 71 g of green crystal powder, 92% of which consists of hexadecachlorophthalocyanine.

C ₃₂ H ₂ N ₈ C ₁₆ (M. 1065.7)

Ber. C 36.1, N 10.5, Cl 53.2%,
found C 35.9, NIl ₁ O, Cl 52.7%.

Example 15

The procedure is as indicated in Example 10, except that 80 g of an equimolar mixture of phthalicdinitrile and 4-phenyl-o-phthalodinitrile and 900 g of n-pentanol are used as the organic liquid.
Temperature: 90 ° C,
Cathodic current density: 1000 A / m ² ,
Yield: 75 g of greenish blue crystal powder, 93% of which consists of diphenyl phthalocyanine.

16

Ber. C 79.3, H 3.9, N 16.8%,
found C 78.5, H 4.0, N 173%

b0

Ber. C 82.1, H 4.2, N 13.7 <> / o,
found C 82.0, H 43, N 13.5%.

Example 12

The procedure indicated in Example 11 is used however, diethylene glycol as an organic liquid

example

The procedure is as indicated in Example 1, but an expanded metal cathode made of stainless chromium and nickel is used! containing stainless steel and an anode, which consists of about 60 μm thick borated nickel on the surface. After working up, 95 g of PC are obtained; Purity 98.7%; specific surface area according to BET6m ² / g.

C3 ₂ Hi ₈ N ₈ (M.514.6)

Ber. C 74.7, H 3.5, N 21.8%,
found C 74.5, H 3.7, N 21.6%.

Example 17

The procedure described in Example 1 is followed, but the electrolytically conductive compound is used equal amount of sodium salt of ß-hydroxypropane

27 Π 005

sulfonic acid and, as organic liquid, n-propanol. After working up, 93 g of PC are obtained; Purity 95%; specific surface 6 mVg.

Example 18

The procedure described in Example 1 is used

but instead of sodium methylate and tetraethyl 'ammonium ethyl sulfate 10 g sodium sulfide. After this

Working up gives 92 g of PC; Purity 98.0%;

specific surface 6.5 mVg.

C ₃₂ H ₁₈ N ₈ (M 514.6)

Ber. C 74.7, H 3.5, N 213%, found C 74.4, H 3.6, N 21.7%.

Example 19

An electrolysis cell with a stainless cathode containing chromium and nickel and a graphite anode coated on the surface with nickel boride (surface: 50 cm ² ) contains a solution of 100 g of o-phthalonitrile, 2 ^ g of sodium methylate and 20 g of tetraethylammonium ethyl sulfate in 720 g of isobutanol and 180 g of ethanol (as a hydrogen-releasing agent). The electrolysis takes place at 80 ° C. with a current density of 2000 A / m ² at the cathode. The hydrogen overvoltage was below 50OmV (measured against the reversible hydrogen electrode in the same medium).

The reaction is ended after 12 Ah

Yield: 60 g PC; Purity 88%; BET specific surface area 5 m ² / g.

C32H, ₈ N _g (M.514.6)

Ber. C 74.7. H 3.5, N 21.8%, found C 74.1, H 3.5, N 21.5%.

Example 20

A solution of 60 g of o-phthalonitrile, 600 g of n-propanol, 2 g of sodium chloropropyl sulfate and 0.5 g of sodium methylate is placed in an electrolysis cell with nickel anode and brass cathode coated with nickel IH boride. The electrolysis is carried out at + 85 ° C with introduction of hydrogen at a current density of 1800 A / m ² cathode surface. According to the theoretical current conversion of 90%, based on o-phthalonitrile, 52 g of phthalocyanine are obtained, which have a purity of 97% having

Example 21 In the electrolytic cell given in Example 20,

ι s however with graphite anode, a solution is made from 60 g of o-phthalonitrile, 600 g of n-propanol, 1 g

Sodium methylate and 5 g sodium chloropropyl sulfonate

up to a theoretical electricity conversion of 80%, based on o-phthalonitrile, Die Strom density is 1500 A / m ² . Become out of the electrolyte 44 g of o-phthalocyanine isolated; Pure content 95%.

The same result is obtained if the chloropropyl sulfonate is replaced by the same amount of potassium xylene or toluene sulfonate

Example 22

In the electrolysis cell mentioned in Example 20, an electrolyte made from 65 g of o-phthalonitrile, 600 g of n-propanol, 5 g of the sodium salt of sulfosuccinic acid, 1 g

jo sodium methylate at + 88 ° C with a cathodic current density of 1800 A / m ² up to a theoretical current conversion of 90%, based on o-phthalonitrile, electrolyzed 56 g of phthalocyanine are isolated from the electrolyte; Purity 97%. After adding

js of a further 58 g of o-phthalonitrile to the phthalocyanine-free electrolyte are added after introducing the the same amount of electricity again isolated 56 g of phthalocyanine. The purity is 96.5%.

909 639/436

Claims (5)

Claims; ! Process for the direct production of metal-free phthalocyanines from aromatic o-dinitriles in solvents under heat, characterized in that primary, secondary or tertiary C _r to C _t2 -alkanols, C ₂ - to Ce-alkanediols, C ₃ - to Ce-alkanediols, poly-C _r to Ce-alkanediols, poly-C ₃ - to Q-alkanetriols, saturated cyclic ethers with 4 and 5 carbon atoms, N-Cr to Q-alkyl or N, N-bis ( Ci- to C-alkyl carboxamides of aliphatic Ci- to C ₃ -carboxylic acids, cyclic N-Ci- to C-alkyl carboxamides with 4 to 6 carbon atoms or mixtures thereof, benzene hydrocarbons or chlorinated benzene hydrocarbons, the small amounts of dissolved electrolytically conductive tetraalkylammonium salts, tris {hydroxyalkylammonium salts! ) -alkylamnionium salts, tetra (hydroxyalkyl) -ammonium salts, salts of primary, secondary or tertiary alkylamines or hydroxyalkylamines with 1 to 20 carbon atoms in the alkyl and / or 2 or 3 carbon atoms in the hydroxyalkyl of hydrochloric acid, sulfur acid, Ci- to C ₈ -alkanesulfonic acid, benzenesulfonic acid, Q- to Cg-alkylbenzenesulfonic acid, Ci- to Cs-alkylsulfuric acid, mono- and / or di-Ci- to Qe-alkyl phosphoric acid; Ammonium salts, alkali metal or alkaline earth metal salts of benzenesulphonic acid, of Q- to Cig-alkylbenzenesulphonic acids, of naphthalenesulphonic acids, of Ci- to Cg-alkylnaphthalenesulphonic acids, of Ci- to Ce-alkanesulphonic acids, of C ₂ - to Q-chloroalkanesulphonic _{acids, of hydroxy-C 2} - to Q-alkanesulfonic acids, the Ci- to Ce-alkylsulfuric acids, the C ₂ - to Ce-chloroalkylsulfuric acids, the mono- or di-Cr to Cie-alkylphosphoric acids, the mono- and di-Cr to Qg-alkyl esters of boric acid, the cyclic Esters of boric acid with 1,2- and 1,3-diols and / or of C4- to Ce-dicarboxylic acids bearing sulfonic acid groups; Ci- to C _{) 2} alkanolates, C ₂ - to CVGIykolaten, hydroxides, amides, sulfides, rhodanides and / or cyanides of the alkali metals and alkaline earth metals, magnesium or lithium chloride contain dissolved or suspended dinitriles in the presence of hydrogen or hydrogen under the reaction conditions eliminating compounds and in the presence of alkali metal alcoholates ^ alkali metal sulfides, alkali metal hydroxides, alkali metal cyanides, alkali metal salts of mono- and di-Ci- to Cie-alkyl phosphoric acids, alkali metal amides, alkali metal salts of mono- and di-alkali metal acid esters of alkyl and di-alkali metal esters of the alkyl metal esters with 1,2-, 23- and 1,3-diols and / or alkali metal salts of sulfonic acid groups-bearing C ₄ - to Ce dicarboxylic acids as alkaline activators using electrodes inert under the reaction conditions so that the hydrogen overvoltage at the cathode is 500 mV (measured against the reversible hydrogen electrode in a medium of the same composition as the reaction mixture) does not exceed. 2. The method according to claim 1, characterized in that the organic liquid Ci- bis Cs-alkanols used. 3. The method according to any one of claims I or 2, characterized in that the electrolytic conductive compounds in an amount of 0.01 and 3% by weight, based on the organic liquid, applies 4. The method according to any one of claims 1 to 3, characterized in that the activators in an amount of 0.1 to 1.0 wt .-%, based on the organic liquid, applies. 5. The method according to any one of claims 1 to 4, characterized in that the electrolysis at temperatures between 60 ° C and the boiling point of the organic liquid